Around device interaction (ADI) is being increasingly investigated as an efficient interaction technique for mobile and/or tangible electronic devices. In this context, ADI relates to human-computer-interaction between a user and an electronic device based on the recognition of gestures of the user in the proximity of the electronic device. Such ADI can provide possibility of extending interaction space of small mobile devices beyond their physical boundary allowing effective use of the three dimensional (3D) space around the device for interaction between a user and the device. This can be especially useful for small tangible/wearable mobile or controller devices such as cell phones, wrist watches, headsets, personal digital assistants (PDA), media players etc. In these devices, it is usually comparably difficult to operate small buttons and touch screens particularly since parts of the touch screen are usually covered by the hand of the user during interaction.
For preventing these drawbacks and in particular for using the space beyond a device which can be easily used no matter how small the device is, a plurality of ADI concepts have been developed which are based on the use of different sensory inputs such as camera, infrared distance sensors, touch sensor at the back of device, etc. These concepts can allow coarse movement-based gestures made in the 3D space around the device to be used for sending different interaction commands such as turning pages (in an e-book or calendar), changing sound volume, zooming, rotation, etc. For example, the publication “HoverFlow: expanding the design space of around-device interaction” of Kratz, S. and Rohs, M., published by proceedings of the 11th International Conference on Human-Computer Interaction with Mobile Devices and Services, Bonn, Germany, September 2009, describes an ADI interface that allows mobile devices to track coarse hand gestures performed above the device's screen. Thereby, infrared proximity sensors are used to track hand and finger positions in the device's proximity. The hand or finger gestures are detected using a specific algorithm and a rough overview of the design space of according ADI-based interfaces is provided. However, the ADI concepts of the prior art all rely on specific physical arrangements which are not standard in electronic devices today. Consequently, the implementation of these ADI concepts is rather complex and expensive. Further, most of these ADI concepts, in particular the ADI concepts allowing for a contactless interaction between the user and the device, require visual contact between the hand/finger of the user and the device. This can constrict the application of the ADI concepts.